How are you conscious of types without any tooling? And if you use tooling, then what's the difference?
For example, JavaScript default args are really helpful for avoiding type errors:
const nameString = (name = {}) => { return `${name.first} ${name.last}`; };
Here, because I set a default expected type (technically speaking), I get back an empty string without runtime errors. If I get an empty string during dev in my UI, I know to go handle the case, or, write a test to call my attention to the problem (often unnecessary because the "bug" is a design issue).
basically you just described dynamic languages here. We know why and how to program in a dynamic language. We don’t want that though. People that are using TypeScript are using it for the static typing.Well, in your example, with default params, you get back an "undefined undefined", not an empty string, so even simple code is sometimes easy to get wrong. Proper amount of typing actually helps a lot to avoid it.
Just let the computer handle this trivia and concentrate your efforts on adding value I say. Sure it takes an hour or two to set up the tooling, but once you are up and running there is no overhead (unless you consider defining types an overhead). Compiles take a fraction of a second and the browser has usually already reloaded itself before you've even physically moved your eyes over to the other monitor
Using typescript is very progressive, you can add types line by line if you want. There's not much setup really other than using TSC to compile the files.